1. Field of the Invention
This invention relates to conducting an inventory of a data storage library and more particularly relates to conducting an inventory of a data storage library with a plurality of cartridge information detectors.
2. Description of the Related Art
Automated data storage libraries are known for providing cost effective storage and retrieval of large quantities of data. The data in automated data storage libraries is stored on data storage media that are, in turn, stored on storage shelves or the like inside the library in a fashion that renders the media, and its resident data, accessible for physical retrieval. Such media is commonly termed “removable media.”
Data storage media may comprise any type of media on which data may be stored and which may serve as removable media, including but not limited to magnetic media (such as magnetic tape or disks), optical media (such as optical tape or disks), electronic media (such as PROM, EEPROM, flash PROM, CompactFlash™, Smartmedia™, Memory Stick™, etc.), or other suitable media. Typically, the data stored in automated data storage libraries is resident on data storage media that is contained within a cartridge and referred to as a data storage media cartridge. An example of a data storage media cartridge that is widely employed in automated data storage libraries for mass data storage is a magnetic tape cartridge.
In addition to data storage media, automated data storage libraries typically include an accessor for transporting cartridges and conducting an inventory. The standard approach to conducting an inventory of a data storage library includes equipping the accessor with a cartridge detector and transporting the detector to read cartridge labels throughout the library. Though conducting an inventory by this means is effective to some extent, the current implementation includes a variety of short comings.
In an inventory system with only one detector, the detector may only read one type of information. For example, a bar code scanner can only obtain inventory information from cartridges with a bar code. Accordingly, the bar code scanner is unable to ascertain if a cartridge is present but has no bar code, if a cartridge is not present, or if a cartridge is present with an unreadable bar code. Additionally, having only one detector requires the accessor to conduct an inventory one storage slot at a time, thereby prolonging the time required to conduct the inventory. In other words, single-detector inventory systems are time-consuming and often unable to conduct a complete inventory.
Additionally, if the detector on the accessor breaks or otherwise ceases to function properly, the library has no backup means for conducting an inventory. Accordingly, an inventory cannot be taken until the library is shutdown and the detector is manually replaced. Thus, in addition to functioning slowly and collecting incomplete inventory data, single-detector systems often present formidable delays in the event of a detector malfunction.
From the foregoing discussion, it should be apparent that a need exists for a system, apparatus, and method that provide an expedited means for conducting a complete inventory. Beneficially, such a system, apparatus and method would decrease inventory time and increase the quality and completeness of the inventory data, in addition to providing a backup in the event of a detector malfunction.